It is necessary to assign a text file to compile and run this program? My code:

program reverseroot;

VAR
a:array[1..1000000] of extended;
i,n:integer;
equal:real;


begin
read(n) {reading range}
for i:=1 to n do
read(a[i]);
for i:=n downto 1 do
writeln(sqrt(a[i]):0:4);

end.